## Wild About Math bloggers 12/31/10

[ The new edition of Wild About Math Bloggers! is at Equalis. Here's the previous edition. ]

Here's our last Wild About Math Bloggers! of the year. Sit back and enjoy this week's ride.

The Mathematics and Multimedia Blog Carnival #6 is now posted at Great Maths Teaching Ideas.

Stephen Wolfram tells, at the Wolfram Blog, about his new venture: Touch Press. I've been waiting for some time for someone to venture beyond the simple ebook to do something more impressive than just providing text to read on an electronic device. Well, Touch Press has done it. Combine text with graphics and live interaction throw in a hefty dose of mathematica under the hood and you have something worth checking out.

It’s a really neat book. There’s something very compelling about being able to spin planets and moons with your finger—and seeing actual spacecraft imagery on all of them. But as I click around exploring the final version of the book, what I’m most struck by is the diversity of innovation in it. Some pages have 3D rotatable objects. Some have computations to run. Some have cutaways revealed by stroking your finger. And yet others have little embedded videos that come to life in a way that nicely complements reading the text. (And of course many pages access Wolfram|Alpha to get detailed, live, astronomical information.)

RJ Lipton has an intriguing article, Unexpected Connections In Mathematics, which serves as a great reminder to us all that one of the most joyful aspects of mathematics is the connection one finds between areas that seem totally unrelated. Hat tip to Shecky.

Dave Richeson, at Division by Zero, shares three fascinating geometric theorems. Check out the third one. It looks easy but geometric proofs are very difficult to come by.

Here's a perplexing problem from Futility Closet. I don't know the answer to this problem. Can you figure it out?

Well, it’s our old friend the mysterious pouch. Today the pouch contains a random quantity of marbles, and we’re going to withdraw a handful. But first, consider:

- If the bag contains an even number of marbles, then we are equally likely to withdraw an even or an odd number. For instance, if it contains 4 marbles, then we are equally likely to withdraw 2 or 4 as 1 or 3.
- But if the pouch contains an odd number of marbles, then we’re more likely to withdraw an odd number, as there’s one more way of choosing an odd number than an even number. For example, if the pouch contains 5 marbles then we’re more likely to draw 1, 3, or 5 than 2 or 4.
This is troubling. Without even opening the pouch we seem to have decided that, on balance, we’re more likely to withdraw an odd number of marbles than an even. Indeed, this seems to mean that handfuls in general are more commonly odd than even. How can this be?

Check out this very eerie iPhone magic trick. Ok, so this one doesn't have anything to do with Math but you'll forgive me after you watch the video.

[youtube]http://www.youtube.com/watch?v=_zkDtf3r8WU[/youtube]

Hat tip to Grey Matters.

Bill Lombard at Mr. L's Math has a great article, Geogebra 2010, The Year in Review. Did you know that:

- There were three International GeoGebra Conferences in 2010
- 3 million netbooks with GeoGebra were given to students in Argentina. Similar projects are running in Australia and Europe.
- 3.8 Million Downloads of GeoGebra this year

See more impressive Geogebra stats at Mr. L's Math.

Finally, check out this fun Math-based scam at Scam School. This is yet another fun application of digital roots, aka "9 is your friend in base 10."

[youtube]http://www.youtube.com/watch?v=ADJx8gmMp-s[/youtube]

I wish every one of you a happy and healthy new year.

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